DAVIS -- Many scientists are linking the increasing intensity of California's droughts to greenhouse gases, and a new study from UC Davis researchers shows the effects of those gases on the state's native plants.

This research team used satellite imagery and data to come up with vegetation maps under different greenhouse gas levels. By comparing conditions where plants are thriving or struggling, researchers predicted what will happen if global warming trends continue unchecked. Struggling vegetation shows up as red.

“Business as usual, by end of the century, fully half of the state is in a high level of background risk," researcher Jim Thorne said.

Much of the effects will occur in the Sierra Foothills, just outside Sacramento.

"The mid-elevations of the Sierra Nevada is an area that looks like it will get a lot of stress," Thorne said.

While the UC Davis study focuses on the effects of greenhouse gases on vegetation, you can’t talk about that subject without also talking about water -- or the lack of it.

We already know that 127 million trees have died in the state, many of them attacked by pests and disease after a lack of water.

Scientists have predicted that global warming will cause more extreme weather -- more flooding as well as extended droughts. Thorne says we may be looking at another drought pattern and that's bad news for plants.

"The hotter it gets, the more water they need. So, even if California were to get wetter, the hotter temperatures drive higher plant stress because they’re going to need more water than is coming in," Thorne told FOX40. "The maps show a different result depending on the amount of global warming."

There could less plant stress, for instance, if the Paris Accord reduction goal of 3.6 degrees is met.

"Then we’re looking at 25%, that’s still a lot," Thorne said.

The map forecasts may help policymakers determine what to put at risk under different greenhouse gas conditions.